Send string to PHP script then return

How would I go about sending data from a form to a script which will process it to check some stuff, but then send the data to another script which will find characters and replace them with some code, then once that is complete I want it to send it back to the same script.

But I would of thought that when the 2nd script sends it back it would just restart the 1st script? Unless I add a URL variable which says it has already done this part?

Do ALL browsers support URL variables? That's a proper nooby question but I have never asked so I don't know. If they do then I can use them more.

This is the exact reason why functions are there. You should make the code in each script a function, include the second script into the first, then run the functions in order. Running multiple scripts for one request is very poor programming

How do I pass the data from the 1st script to the next script/function?

Never mind, just read how to on the manual of PHP.

function($string);